A5073189544- Antibiotic Resistance in Bacteria
- Enzyme Structure and Function
- Tuberculosis Research and Epidemiology
- Bacterial Genetics and Biotechnology
- Protein Structure and Dynamics
- Mycobacterium research and diagnosis
- Glycosylation and Glycoproteins Research
- Diagnosis and treatment of tuberculosis
- Carbohydrate Chemistry and Synthesis
- Cancer therapeutics and mechanisms
- Escherichia coli research studies
- Genomics and Phylogenetic Studies
- Trauma, Hemostasis, Coagulopathy, Resuscitation
- X-ray Diffraction in Crystallography
- Microbial Metabolism and Applications
- Antibiotics Pharmacokinetics and Efficacy
- Vibrio bacteria research studies
- Blood properties and coagulation
- Medical Imaging Techniques and Applications
- Enzyme Production and Characterization
- Bacterial biofilms and quorum sensing
- Blood Coagulation and Thrombosis Mechanisms
- Chemical Reactions and Isotopes
Leiden University
2021-2024
Institute of Biochemical Physics NM Emanuel
2017
Abstract Evolution minimizes the number of highly conserved amino acid residues in proteins to ensure evolutionary robustness and adaptability. The roles all conserved, non‐catalytic residues, 11% class A β‐lactamase were analyzed by studying effect 146 mutations on cell vitro activity, folding, structure, stability. Residues around catalytic (second shell) contribute fine‐tuning active site structure. Mutations affect structure over entire can result stable but inactive protein. Conserved...
The β-lactamase BlaC conveys resistance to a broad spectrum of β-lactam antibiotics its host Mycobacterium tuberculosis but poorly hydrolyzes third-generation cephalosporins, such as ceftazidime. Variants other β-lactamases have been reported gain activity against ceftazidime at the cost native activity. To understand this trade-off, laboratory evolution was performed, screening for enhanced variant Pro167Ser shows faster breakdown ceftazidime, poor hydrolysis ampicillin and only moderately...
The current rise of antibiotic resistant forms Mycobacterium tuberculosis is a global health threat that calls for new antibiotics. β-lactamase BlaC this pathogen prevents the use β-lactam antibiotics, except in combination with inhibitor. To understand if exposure to such inhibitors can easily result resistance, evolution experiment was performed, studying evolutionary adaptability against inhibitor sulbactam. Several amino acid substitutions were shown confer reduced sensitivity G132S...
Conserved residues are often considered essential for function, and substitutions in such expected to have a negative influence on the properties of protein. However, mutations few highly conserved β-lactamase from Mycobacterium tuberculosis, BlaC, were shown no or only limited effect enzyme. One mutant, D179N, even conveyed increased ceftazidime resistance upon bacterial cells, while displaying good activity against penicillins. The crystal structures BlaC D179N resting state complex with...
Abstract Evolution leads to conservation of amino acid residues in protein families. Conserved proline are usually considered ensure the correct folding and stabilize three‐dimensional structure. Surprisingly, that highly conserved class A β‐lactamases were found tolerate various substitutions without large losses enzyme activity. We investigated roles three prolines at positions 107, 226, 258 β‐lactamase BlaC from Mycobacterium tuberculosis mutations can lead dimerization an overall less...
Bacillus circulans xylanase (BcX) from the glycoside hydrolase family 11 degrades xylan through a retaining, double-displacement mechanism. The enzyme is thought to hydrolyze glycosidic bonds in processive manner and has large, active site cleft, with six subsites allowing binding of xylose units. Such an architecture suggests that oligomeric substrates can bind multiple ways. In crystal structure catalytically inactive variant BcX E78Q, substrate xylotriose observed site, as well bound...
Evolutionary robustness requires that the number of highly conserved amino acid residues in proteins is minimized. In enzymes, such conservation observed for catalytic but also some second shell or even further from active site. β‐Lactamases evolve response to changing antibiotic selection pressures and are thus expected be evolutionarily robust, with a limited residues. As part effort understand roles class A β‐lactamases, we investigate reasons leading two β‐lactamase BlaC, Glu37, Trp229....
The β-lactamase of Mycobacterium tuberculosis, BlaC, is susceptible to inhibition by clavulanic acid. ability this enzyme escape through mutation was probed using error-prone PCR combined with functional screening in Escherichia coli. variant that found confer the most inhibitor resistance, K234R, as well G132N previously were characterized X-ray crystallography and nuclear magnetic resonance (NMR) relaxation experiments probe structural dynamic properties. mutant exists solution two almost...